The invention relates to exercise apparatus which simulate cross-country skiing.
Various apparatus have been designed to permit cross-country skiers to exercise the muscles necessary for the sport in a stationary location indoors in a gymnasium or the like The purpose of such apparatus is to simulate as closely as possible the movements involved in actual cross-country skiing In the past, such devices have typically included a pair of foot plates mounted on a pair of tracks extending along a base frame. The foot plates connect to endless belts which in turn drive a flywheel. See for example U.S. Pat. No. 4,659,077 issued Apr. 21, 1987 to Fitness Quest Inc., U.S. Pat. No. 4,645,201 issued Feb. 24, 1987 to Tekron Licencing B.V., U.S. Pat. No. 4,434,981 issued Mar. 6, 1984 to Desmond Norton, U.S. Pat. No. 4,023,795 issued May 17, 1977 to Edward Pauls, U.S. Pat. No. 3,941,377 issued Mar. 2, 1976 to Hakon Lye, and the product currently sold under the trademark NORDIC TRACK.
In order to provide simultaneous exercise for the arms through poling motion, such devices have typically had a separate pulley or spring system for each arm which operates independently of the leg motion. The problem with such apparatus is that they do not adequately simulate the sensation of cross-country skiing. In actual cross-country skiing, the energy transmitted through the ski poles creates a gliding sensation which in turn affects the way in which force is transmitted through the leg action. In the prior art devices, however, the amount of exertion applied to the poling action has no effect on the resistance presented to the leg motion. Consequently, the user does not receive the same sensation as actual cross-country skiing and the amount of exercise which the various muscles receive will likely differ from actual skiing. For example, in actual cross-country skiing, the skier may "double pole" for a period of time to build up his momentum. Once he recommences his leg motion, he will already be gliding with some momentum However, in the prior art exercise apparatus, the double-poling motion would not generate any momentum in the flywheel which is driven by the leg motion of the person exercising.
The present invention provides an exercise apparatus for simulating cross-country skiing in which both the poling action and leg action transmit energy to a single flywheel so that the user receives a more realistic simulation of cross-country skiing.